Intelligent hinged boom excavation systems

ABSTRACT

Embodiments of an intelligent hinged boom excavation system include a hinged boom assembly terminating in an excavation tool, an electro-hydraulic (EH) actuation subsystem, and boom assembly tracking sensors providing tracking data indicative of excavation tool movement. A controller architecture is operable in an excavation depth limiting mode in which the controller architecture: (i) tracks a current position of the excavation tool relative to a virtual excavation floor utilizing the tracking data provided by the boom assembly tracking sensors; (ii) determines when an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor by the excavation tool; and (iii) when determining that an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor, controls the EH actuation subsystem to modify the operator-commanded movement in a manner preventing breach of the virtual excavation floor by the excavation tool.

CROSS-REFERENCE TO RELATED APPLICATION(S)

Not applicable.

STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE DISCLOSURE

This disclosure relates to hinged boom excavation systems operable in intelligent control modes, such as an excavation depth limiting mode in which operator input commands are selectively modified to prevent breach of a virtual excavation floor by a backhoe bucket or other boom-mounted excavation tool.

BACKGROUND OF THE DISCLOSURE

Certain work vehicles are commonly equipped with hinged boom excavation assemblies terminating in an excavation tool, such as a backhoe bucket, an auger, a trencher implement, or a hydraulic hammer. The hinged boom excavation assembly may be produced as a modular unit intended for rapid in-field attachment and detachment by an operator, as in the case of a backhoe attachment for a tractor. Alternatively, the hinged boom excavation assembly may be joined to the chassis of a work vehicle in a non-modular manner not intended for rapid in-field detachment and interchange, as in the case of tracked excavators and some tractor excavators. Whether implemented in a modular or non-modular manner, the hinged boom excavation assembly may be controlled utilizing an electrohydraulic (EH) control scheme carried-out by an electronic controller. During operation of the hinged boom excavation assembly, operator input commands entered via an operator interface (e.g., including joysticks or similar manual controls) are transmitted to the controller, which converts the operator input commands into corresponding valve control signals. The valve control signals are then transmitted to valve actuators, which modulate flow control valves to vary hydraulic fluid flow to hydraulic cylinders integrated into the hinged boom assembly. In response to such changes in hydraulic fluid flow, the hydraulic cylinders extend or retract, as appropriate, to move the hinged boom excavation boom assembly and, specifically, the excavation tool in the manner commanded by the work vehicle operator.

SUMMARY OF THE DISCLOSURE

In various embodiments, an intelligent hinged boom excavation system includes a hinged boom assembly terminating in an excavation tool, an electro-hydraulic (EH) assembly, and boom assembly tracking sensors coupled to the hinged boom assembly and configured to provide tracking data indicative of excavation tool movement. A controller architecture is coupled to the EH actuation subsystem and to the boom assembly tracking sensors. The controller architecture is operable in an excavation depth limiting mode in which the controller architecture: (i) tracks a current position of the excavation tool relative to a virtual excavation floor utilizing the tracking data provided by the boom assembly tracking sensors; (ii) determines when an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor by the excavation tool based, at least in part, on the current position of the hinged boom assembly; and (iii) when determining that an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor, controls the EH actuation subsystem to modify the operator-commanded movement in a manner preventing breach of the virtual excavation floor by the excavation tool.

In further embodiments, the intelligent hinged boom excavation system includes an EH actuation subsystem including hydraulic cylinders integrated into the hinged boom assembly, boom assembly tracking sensors coupled to the hinged boom assembly and configured to provide tracking data indicative of excavation tool movement, and an Operator interface configured to receive operator input commands directing movement of the hinged boom assembly. A controller architecture is coupled to the EH actuation subsystem, to the operator interface, and to the boom assembly tracking sensors. The controller architecture is configured to: (i) utilize the tracking data provided by the boom assembly tracking sensors to track a current position of the excavation tool relative to a two dimensional plane defining a boundary of an excavation feature desirably created utilizing the excavation tool; and (ii) control the EH actuation subsystem to move a cutting edge of the excavation tool along the two dimensional plane without breach thereof in response to operator input commands received via the operator interface.

The details of one or more embodiments are set-forth in the accompanying drawings and the description below. Other features and advantages will become apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

At least one example of the present disclosure will hereinafter be described in conjunction with the following figures:

FIG. 1 is a side view of a work vehicle (here, a tractor) equipped with an intelligent electrohydraulic (EH) hinged boom excavation system (here, an intelligent backhoe system), as illustrated in accordance with an example embodiment of the present disclosure;

FIG. 2 is a perspective view of the intelligent EH backhoe system shown in FIG. 1, including several windows illustrating selected components of the example backhoe system in greater detail;

FIG. 3 is a side schematic view of the example intelligent EH backhoe system shown in FIGS. 1 and 2 illustrating positions at which rotary position sensors and pressure sensors may be integrated into the hinged boom assembly in embodiments;

FIG. 4 is a side schematic view of the hinged boom assembly shown in FIG. 3 illustrating the potential for operator error in inadvertently digging an excavation feature to an excessive depth absent the excavation depth limiting function provided by embodiments of the intelligent EH backhoe system;

FIG. 5 is a flowchart of an example process suitably carried-out by the controller architecture of intelligent EH backhoe system (FIGS. 1-3) to perform an excavation depth limiting function and possibly other control functions when utilizing the backhoe system to create an excavation feature;

FIGS. 6-9 illustrate, in sequence, an example manner in which the hinged boom assembly of the intelligent EH backhoe system may translate operator input commands into movement of a cutting edge of the backhoe bucket along a virtual excavation floor without breach thereof; and

FIG. 10 is an isometric view of a tractor excavator equipped with an intelligent EH backhoe system and further illustrating two axes (pitch and roll) about which an operator may rotate the virtual excavation floor in at least some embodiments of the present disclosure.

Like reference symbols in the various drawings indicate like elements. For simplicity and clarity of illustration, descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the example and non-limiting embodiments of the invention described in the subsequent Detailed Description. It should further be understood that features or elements appearing in the accompanying figures are not necessarily drawn to scale unless otherwise stated.

DETAILED DESCRIPTION

Embodiments of the present disclosure are shown in the accompanying figures of the drawings described briefly above. Various modifications to the example embodiments may be contemplated by one of skill in the art without departing from the scope of the

Overview

Intelligent control systems have been developed for guiding tool or implement movement in the context of certain work vehicles, such as intelligent control systems for positioning the blades of motor graders. However, there exist relatively few, if any intelligent control systems for guiding the movement of hinged boom excavation assemblies, while meeting the unique needs of such excavation assemblies. This industrial deficiency results in lowered productivity and increased opportunities for human error when, for example, a hinged boom excavation assembly is utilized to dig an excavation feature, such as a trench, to specifications. Absent intelligent guidance of the hinged boom excavation assembly, an operator may have difficultly correlating movement of the excavation tool with operator input commands considering, in particular, that conventional control schemes involve rotational control of the boom assembly linkage about multiple pin or pivot joints of the boom assembly linkage resulting in non-linear movement of the excavation tool. The ability of an operator to intuitively predict excavation tool movement for a given set of operator input commands may be further degraded when the work vehicle is supported by non-level terrain, which tilts the work vehicle chassis about its roll and/or pitch axes. Moreover, it can be difficult for an operator, seated in an operator station of the work vehicle, to judge with high degree of accuracy the spatial relation between the excavation area in which an excavation feature is desirably created and the excavation tool position as the excavation tool travels through a three dimensional (3D) volume of space (herein, the “tool space”) during an excavation task.

For at least these reasons, an operator may create an excessively deep trench or similar excavation feature when conducting an excavation operation utilizing a conventional, unguided hinged boom excavation assembly. The creation of such an excessively deep trench risks inadvertent contact between the excavation tool and pipes, conduit lines, or other buried objects within the ground. Additionally, the task of digging an excavation feature to specifications (e.g., a desired shape and dimensions) becomes further complicated in instances in which the floor of the excavation feature is desirably imparted with a targeted grade (a specific incline or decline), again introducing additional opportunity for human error and exacerbating the mental workload placed on the operator during the excavation task. As a still further challenge, operators routinely find it difficult to control a hinged boom excavation assembly in a manner moving a cutting edge of the excavation tool along a sidewall of an excavation feature to provide a relatively planar or “clean” cut. This may be the case when an operator attempts to clean the surface of an excavation feature located closest the work vehicle (commonly referred to as the “backface” of the excavation feature), as this surface typically remains blocked from the operator's direct line-of-sight (LOS) during an excavation operation without repositioning of the work vehicle.

There thus exists an ongoing industry demand for systems including hinged boom excavation assemblies (herein, “intelligent hinged boom excavation systems”) operable in intelligent control or excavation tool guidance modes, which overcome limitations associated with conventional hinged boom excavation assemblies lacking intelligent guidance functionalities. Ideally, such an intelligent hinged boom excavation system would be operable in a tool guidance guidance mode assisting an operator in imparting an excavation feature with a desired shape and dimensions in an intuitive and consistent manner. It would also be desirable for such an intelligent hinged boom excavation system to translate operator input commands into movement of a boom-mounted excavation tool in a predictable manner, regardless of the orientation of the work vehicle chassis during an excavation operation. In still other instances in which an electrohydraulic (EH) actuation subsystem is utilized to effectuate movements of a hinged boom excavation assembly terminating in backhoe bucket or other boom-mounted excavation implement, it would be desirable for the intelligent hinged boom excavation system to be operable in a control mode mitigating stall of the EH actuation subsystem and other overload conditions.

Embodiments of an intelligent hinged boom excavation system providing such functionalities are disclosed herein. Addressing first the excavation depth limiting function performed by some (but not necessarily all) embodiments of the intelligent hinged boom excavation system, when activated, this function prevents (or at least deters) an operator from controlling a hinged boom excavation assembly to dig an excavation feature to an excessive depth. In various implementations, one or more controllers (herein, the “controller architecture”) of the intelligent hinged boom excavation system utilizes data provided by boom assembly tracking sensors to track the position of the excavation tool relative to a virtual excavation floor. The boom assembly tracking sensors can include any type and number of sensors for monitoring the movement of the excavation tool relative to the chassis of the work vehicle or other fixed reference point. For example, in one approach, rotary position sensors are integrated into the pivot joints of the boom assembly linkage; and the angular displacement readings captured by the rotary position sensors, taken in conjunction with known dimensions of the boom assembly linkage, are utilized to track the position of the excavation tool and, perhaps, specifically track the position of a cutting edge of the excavation tool in the 3D tool space. Other sensor inputs can also be considered in addition or lieu of such rotational position readings, such as linear displacements of hydraulic cylinders integrated into the boom assembly, inertia-based sensor readings (as captured by microelectromechanical (MEMS) devices, such as MEMS accelerometers or gyroscopes, incorporated into the boom assembly), measurements captured by sensors indicative of a current orientation of the work vehicle chassis (e.g., MEMS devices, inclinometers, or similar sensors attached to the work vehicle chassis), and/or vision system tracking of the excavation implement, to list but a few examples.

Regardless of the particular manner in which the excavation tool is tracked, the controller architecture repeatedly determines or predicts when an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor by the excavation tool based, at least in part, on the current position of the hinged boom assembly. When determining that an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor, the controller architecture controls the hinged boom excavation assembly (e.g., through commands transmitted to an EH actuation subsystem) to modify the operator-commanded movement in a manner preventing breach of the virtual excavation floor by the excavation tool. Conversely, when determining that an operator-commanded movement of the hinged boom assembly will not.

result in breach of the virtual excavation floor, the controller architecture implements the operator-commanded movement without modification thereof. In this manner, an operator is permitted to control the hinged boom excavation system utilizing a standard control scheme (more colloquially, “dig as usual”) in the envelope of space above the virtual excavation floor. However, should the operator inadvertently attempt to control the hinged boom excavation assembly to move the excavation tool through the virtual excavation floor, the controller architecture will perform certain actions preventing virtual excavation floor breach by the excavating tool. Such actions can include arresting movement of the excavation tool in certain instances (e.g., when the excavation tool is moved essentially along an axis orthogonal to the excavation floor); however, in other instances, the controller architecture advantageously controls the hinged boom excavation assembly to move the excavation tool (e.g., a cutting edge of the excavation tool) along the virtual excavation floor in a direction indicated by the operator input commands.

In embodiments, the controller architecture of the intelligent hinged boom excavation system defines the virtual excavation floor as a two dimensional (2D) plane or boundary within the 3D tool space through which the excavation tool moves. In other embodiments, the controller architecture may define the virtual excavation floor to have a more complex, non-planar topology, such as a curved or stepped surface geometry. In determining whether the execution of operator input commands will result in breach of the virtual excavation floor, the controller architecture considers riot only the current position of the excavation tool and other relevant factors (e.g., the orientation of the work vehicle chassis), but further considers the location and orientation of the virtual excavation floor in the 3D tool space. In embodiments, the controller architecture may determine the location of the virtual excavation floor by locating a point on the virtual excavation floor below a ground height reference point by an excavation depth setting; the excavation depth setting representing a vertical distance (e.g., as measured along a direction parallel to gravity) extending downwardly from the ground height reference point to the floor reference point. The excavation depth setting may be specified by operator input entered utilizing a suitable operator interface, such as a Graphical User Interface (GUI) allowing an operator to enter a desired dig depth into a GUI field as a particular number of feet or meters. Comparatively, the ground height reference point can be determined as a default value, based on operator input, utilizing sensor input indicative of the excavation ground height relative to the work vehicle chassis, or any blended combination thereof.

With respect to utilizing sensor input to determine the excavation ground height, such sensor input can be provided by sensors capable of directly measuring the excavation ground height or level by, for example, measuring energy (e.g., laser, acoustic, or radar) signals reflected from the ground (e.g., as in the case of distance measuring equipment (DME), if present on the work vehicle). In other instances, at least one rotary position sensor may be incorporated into the stabilizer arms of the intelligent hinged boom excavation system, in which case the controller architecture may estimate the excavation ground height based on data from the rotary position sensor(s) indicating the rotational angle of the stabilizer arms when deployed into a ground-contacting position. In such instances in which excavation ground height is measured, the planform coordinates of the ground height reference point may be extrapolated, if needed, from the location at which the excavation ground height measurement is captured.

In further embodiments, the ground height reference point may be established utilizing a calibration process. For example, in one approach, an operator is initially prompted to control the hinged boom excavation assembly in a manner placing the excavation implement in a ground-contacting position over or adjacent the ground region in which an excavation feature is desirably created. The operator further provides input indicating when this task has been completed; and, in response to this operator input, the controller architecture then estimates the current position of the excavation tool to determine the ground height reference point. Specifically, the controller architecture may estimate a current spatial position and orientation of the excavation tool, and then establish the ground height reference point as coincident with a lowermost surface of the excavation tool. An intuitive, operator-driven calibration process is thus provided during which an operator may effectively set the excavation tool on the ground in an excavation area, enter a desired excavation depth below the excavation tool, and then commence digging the excavation feature utilizing the intelligent hinged boom excavation system. Additionally, in certain embodiments, an operator may also be able to specify a grade or slope of the excavation feature floor (or otherwise rotate the virtual excavation plane about its pitch and/or roll axes) prior to conducting the excavation operation, as further discussed below.

In yet other embodiments, the intelligent hinged boom excavation system may enable an operator to establish other virtual (e.g., 2D planar) boundaries of an excavation feature in addition to or in lieu of the above-described virtual excavation floor. For example, in certain instances, the controller architecture may prevent breach of a virtual sidewall of the excavation feature, such as a backface of a trench, during an excavation operation. Further, the controller architecture may modify operator input commands that would otherwise result in breach of the excavation feature backface (or other virtual sidewall) to instead move a cutting edge of the excavation implement along the excavation feature backface. In this manner, an operator can readily control the intelligent hinged boom excavation system to scrape (and thus thoroughly clean) the backface of a trench or other excavation feature, while maintaining the desired dimensions of the excavation feature.

In certain implementations, the intelligent boom excavation system may be operable in other control or excavation tool guidance modes, such as a linear or Cartesian control mode. In this case, the controller architecture may translate operator input commands, such as joystick rotational displacements, into linear movement of the excavation implement along one or more axes. Such a linear control mode may be particularly beneficial when utilized in conjunction with the above-described excavation depth limiting function in which the controller architecture establishes the location and orientation of a virtual excavation floor (or other planar boundary) of the excavation feature. In such embodiments, the controller architecture may translate or convert operator input commands into linear movement of the excavation implement (and, perhaps, specifically linear movement of a cutting edge of the excavation implement) along one or both of: (i) a first axis (or axes) parallel to the virtual excavation floor, and (ii) a second axis (or axes) orthogonal to the virtual excavation floor. A highly intuitively operator control scheme for controlling excavation tool movement during an excavation tasks is thus created by referencing linearized excavation tool movements to a virtual excavation floor in such a manner. This notwithstanding, in other embodiments, operator input commands may be converted or translated to linear movements of the excavation tool along one or more axes oriented with respect to a different frame of reference, such as the chassis of the work vehicle or with respect to the direction of gravity. Various other controls schemes are also possible and equally viable for usage in conjunction with the above-described excavation depth limiting function.

Embodiments of the intelligent hinged boom excavation system may perform other intelligent control functions in addition or in lieu of the above-described excavation depth limiting function. For example, in certain implementations, the controller architecture of the intelligent hinged boom excavation system may be operable in an overload protection mode. When operating in such a mode, the controller architecture may automatically (that is, without requiring operator input) control the EH actuation subsystem to reduce a penetration depth of the excavation tool in response to detection of an overload condition. Such an overload condition may be determined based on an estimated or detected load placed on an engine of the work vehicle. Alternatively, an overload condition may be detected when an expected velocity of the excavation tool exceeds the actual velocity of the excavation tool by a certain margin. In still other instances, the controller architecture may detect the occurrence of an overload condition when determining that the EH actuation subsystem has encountered or will soon encounter a stall condition due to excessive loading of the excavation tool; e.g., by monitoring pressure levels within the hydraulic cylinders or flow circuits of the of the EH actuation subsystem. In this latter instance, the controller architecture may automatically control the EH actuation subsystem to reduce the excavation tool penetration depth to lessen the load resisting motion of the hinged boom assembly and thereby remove or preempt the stall condition.

Example embodiments of work vehicles equipped with intelligent hinged boom excavation system are described below in connection with FIGS. 1-10. First, an example intelligent hinged boom excavation system implemented as an intelligent backhoe system attachment mounted to a tractor is discussed below in connection with FIGS. 1-9. Following this, an example intelligent hinged boom excavation system likewise implemented as an intelligent backhoe system attached to a tractor in a non-modular manner is described below in connection with FIG. 10. The following examples notwithstanding, it is emphasized that embodiments of the intelligent hinged boom excavation system can assume other forms, may be utilized in conjunction with a wide range of work vehicles, and may be implemented in either a modular or a non-modular manner in embodiments. Additionally, in further embodiments, the intelligent hinged boom excavation system may be equipped with an excavation tool other than a backhoe bucket, such as different type of bucket, a trencher implement, an auger, or a hydraulic hammer/breaker.

Example Intelligent Hinged Boom Excavation Systems and Work Vehicles

Referring to FIGS. 1 and 2, an example embodiment of a work vehicle (here, a tractor 20) equipped with an intelligent hinged boom excavation system 22 is presented. In this example, the intelligent hinged boom excavation system 22 assumes the form of a smart or intelligent backhoe system and is consequently referred to hereafter as the “intelligent backhoe system 22.” In addition to the intelligent backhoe system 22, the example tractor 20 includes a front end loader (FEL) assembly 24, a tractor chassis 26 to which the FEL assembly is attached, and a cabin 28 located atop the tractor chassis 26. The tractor chassis 26 is supported by a number of ground-engaging wheels 30, which are driven by an internal combustion engine 32 housed in an engine compartment 34 of the tractor 20. An operator may pilot the tractor 20, operate the FEL assembly 24, and otherwise control the functionalities of the tractor 20 when seated within a first operator station provided within the cabin 28.

In certain embodiments, the tractor 20 may include a single Operator station enclosed by the cabin 28. In such embodiments, operator input controls (e.g., joysticks, levers, buttons, and the like) for controlling the intelligent backhoe system 22 may be located within the cabin 28. Additionally, the seat within cabin 28 may swivel at least 180 degrees to allow an operator to assume a rear-facing seated position when operating the intelligent backhoe system 22 and, specifically, when controlling movements of a hinged backhoe assembly 46 included in the backhoe system 22. Alternatively, and as indicated in the example of FIGS. 1 and 2, the tractor 20 may further include a second operator station 36 (herein, the “backhoe operator station 36”), which may be provided as part of a tractor backhoe attachment. In this example, the backhoe operator station 36 includes a rear-facing seat 38, a display device 40, and an operator interface (including various operator input controls 42, 43, 44) for controlling movement of the hinged backhoe assembly 46. More specifically, an operator may interact with the input controls 42, 43, 44, here including first and second joysticks 42, 44, to control movement of a backhoe bucket 48 (generally, an “excavation tool”) in which the hinged backhoe assembly 46 terminates.

In addition to the backhoe bucket 48, the hinged backhoe assembly 46 further includes a backhoe attachment frame 50, an inner or proximal boom 52 (hereafter “the hoist boom 52”), and an outer or distal boom 54 (hereafter “the dipperstick 54”). The backhoe attachment frame 50 also includes a notched tractor mount end 60, which can be attached to the rear or aft end of the tractor chassis 26 utilizing suitable hardware, such as removable pins. Twin stabilizer arms 56 are hinged joined to opposing sides of the backhoe attachment frame 50. The stabilizer arms 56 are rotatable between a stowed or retracted position and a deployed or extended position (shown). The stabilizer arms 56 may be rotated into the ground-engaging, deployed position by extension of a pair of hydraulic stabilizer cylinders 58 prior to performance of an excavation task. An operator may command rotation of the stabilizer arms 56 into the deployed position utilizing, for example, the lever 43 included in the operator interface of the intelligent backhoe system 22.

During operation, the hinged backhoe assembly 46 is animated by extension and retraction of a number of hydraulic cylinders 62, 64, 66, 68 included within an EH actuation subsystem 70 (FIG. 1). These hydraulic cylinders include swing cylinders 62, a hoist boom cylinder 64, a dipperstick cylinder 66, and a bucket cylinder 68. Extension and retraction of the swing cylinders 62 rotates the hoist boom 52 (and therefore the dipperstick 54 and backhoe bucket 48) about a vertical axis relative to the backhoe attachment frame 50 and the tractor chassis 26. Extension and retraction of the hoist cylinder 64 rotates the hoist boom 52 about a first pivot joint at which the hoist boom 52 is joined to the backhoe attachment frame 50. Extension and retraction of the dipperstick cylinder 66 rotates the dipperstick 54 about a second pivot joint at which the dipperstick 54 is joined to the hoist boom 52. Finally, extension and retraction of the bucket cylinder 68 rotates or “curls” the backhoe bucket 48 about a third pivot joint at which the bucket cylinder 68 is joined to the dipperstick 54. Although not shown in FIGS. 1 and 2 for clarity, the EH actuation subsystem 70 also contains various other hydraulic components, which may include flow lines (e.g., hoses), pumps, a surnp, fittings, relief valves, filters, and the like. The EH actuation subsystem 70 also includes electronic valve actuators and flow control valves, such as spool-type multi-way valves, which can be modulated to regulate the flow of pressurized hydraulic fluid to and from the hydraulic cylinders 58, 62, 64, 66, 68. As indicated by the detail window appearing in the lower right of FIG. 2, the flow control valves and possibly the valve actuators may be consolidated into a control valve bank 72 installed within the hinged backhoe assembly 46 at a location generally beneath operator seat 38.

A controller architecture 74 (FIG. 1) controls the operation of intelligent backhoe system 22. The controller architecture 74 can assume any form suitable for performing the control and excavation implement guidance functions described throughout this document. The term “controller architecture,” as appearing herein, is utilized in a non-limiting sense to generally refer to the processing architecture of the intelligent backhoe system 22 (or other intelligent hinged boom excavation system). The controller architecture 74 can thus encompass or may be associated with any practical number of processors (central and graphical processing units), individual controllers, computer-readable memories, power supplies, storage devices, interface cards, and other standardized components. For example, in one implementation, the controller architecture 74 may include a combination of multiple controllers, such as a backhoe attachment controller, a valve controller, and/or a vehicle (tractor) controller. Further underscoring this point, FIG. 2 depicts (in an enlarged format) an individual controller unit 76 that may be installed within the backhoe assembly 46. A symbol 78 adjacent controller unit 76 denotes that multiple such controller units 76 may be included in the intelligent backhoe system 22 and operably interconnected by a bus or other data-communication connection. The controller architecture 74 may also include or cooperate with any number of firmware and software programs or computer-readable instructions designed to carry-out the various process tasks, calculations, and control/display functions described herein. Such computer-readable instructions may be stored within a non-volatile sector of a memory 80 associated with (accessible to) the controller architecture 74. While generically illustrated in FIG. 1 as a single block, the memory 80 can encompass any number and type of storage media suitable for storing computer-readable code or instructions, as well as other data utilized to support the operation of the intelligent backhoe system 22. The memory 80 may be integrated into the controller architecture 74 in embodiments as, for example, a system-in-package, a system-on-a-chip, or another type of microelectronic package or module.

The intelligent backhoe system 22 further includes a plurality or array of sensors 82, as schematically represented in the upper left of FIG. 1. The sensor array 82 includes boom assembly tracking sensors 84 for tracking the movement and positioning of the backhoe bucket 48 in three dimensional space. The boom assembly tracking sensors 84 can include any number and type of sensors for monitoring the position and movement characteristics of the backhoe bucket 48. In various embodiments, the boom assembly tracking sensors 84 may include rotary position sensors for monitoring movement of the boom assembly linkage about its pivot joints. In such embodiments, the rotary position sensors may be incorporated into the pivot joints of the boom assembly linkage and, perhaps, integrated directly into the backhoe structure pins. An example of one such rotary position sensor 85 appears in the upper right detail window shown in FIG. 2. In this example, the sensor 85 assumes the form of a rotary position sensor, such as a rotary variable displacement transducer (RVDT) or potentiometers, for detecting the rotation displacement of the dipperstick 54 relative to the hoist boom 52 about a pin or pivot joint 98. Referring also to FIG. 3 in conjunction with FIGS. 1 and 2, and as indicated by symbols 88 and key 90 in FIG. 3, similar rotational displacement sensors may also be integrated into a pin or pivot joint 96 formed between the backhoe attachment frame 50 and the hoist boom 52, as well as a pin or pivot joint 100 formed between the dipperstick 54 and the backhoe bucket 48. Such a rotary displacement sensor may also be provided for measuring the swing angle of the hinged backhoe assembly 46 relative to the backhoe attachment frame 50, and therefore the tractor 20, as taken about the X-axis of a coordinate legend 92 further appearing in FIG. 3.

In further embodiments, the boom assembly tracking sensors 84 may include other types of sensors for monitoring the movement of the backhoe bucket 48 in the 3D tool space. Such other sensors can include, for example, linear variable displacement transducers (LVDTs) or other such linear displacement sensors for measuring the stroke of the hydraulic cylinders 62, 64, 66, 68, which can then be converted to angular positions of the boom assembly linkage. Additionally or alternatively, MEMS devices, such as a MEMS accelerometers and gyroscopes packaged as Inertial Measurement Units (IMUs) can be mounted to the tractor chassis 26, to the hoist boom 52, to the dipperstick 54, to the backhoe bucket 48. Such MEMS devices may then communicate with the controller architecture 74 over wired or wireless connections to provide acceleration and/or angular displacement data utilized by the architecture 74 in tracking the movement and position of the backhoe bucket 48. In still other embodiments, the boom assembly tracking sensors 84 may include one or more cameras having fields-of-view encompassing the 3D tool space through which the backhoe bucket 48 travels, in which case the controller architecture 74 may track backhoe bucket position by visual analysis of the camera feeds. In yet further implementations, other types of boom assembly tracking sensors may be utilized and integrated into the hinged backhoe assembly 46. Finally, as further indicated in FIG. 1, the sensor array 82 may also include one or more sensors 102 for monitoring the orientation of the tractor chassis 26, such as MEMS devices, inclinometers, or the like mounted to the chassis 26. In this manner, the controller architecture 74 can consider the orientation of the tractor chassis 26 when tracking the movement of the backhoe bucket 48, such as when the hoist boom 52 is swung relative to the backhoe attachment frame 50 around a vertical axis (which may vary relative to the direction of gravity in instances in which the tractor orientation is offset from a purely horizontal or flat orientation).

The sensor array 82 of intelligent backhoe system 22 may further include other types of sensors 110 in addition to sensors for monitoring the orientation of the tractor chassis 26 and the movement of the boom assembly linkage. Such other sensors 110 may include one or more sensors providing data indicative of the local ground level or height, as measured relative to the backhoe attachment frame 50, relative to the tractor chassis 26, or relative to another fixed reference point. Additionally or alternatively, such other sensors 110 can include sensors for measuring the forces resisting movement of the hinged backhoe assembly 46 when performing an excavation task. In certain cases, such sensors 110 may directly measure or estimate load placed on the engine 32 of the tractor 20. In other instances, such sensors 110 may measure hydraulic fluid pressures within the hydraulic cylinders 64, 66, 68 integrated into the hinged backhoe assembly 46 or hydraulic fluid pressures within the flow network of the EH actuation subsystem 70. This is further indicated schematically in FIG. 3 by symbols 104, which represent pressure sensors integrated into each of the hydraulic cylinders 64, 66, 68. The pressure readings received from the pressure sensors 104, or other pressure sensors, may be considered by the controller architecture 74 when carrying-out an overload protection function, as described more fully below in connection FIG. 5.

As noted above, the sensor array 82 may include additional sensors 110 for estimating a local ground level or height in embodiments. In such embodiments, the tractor 20 may be equipped with rear-facing DME or similar obstacle detection sensors, which can be utilized by the controller architecture 74 to estimate the excavation ground height to the rear of the tractor 20. In other instances, the sensors 110 may include at least one rotary position sensor (e.g., an RVDT or potentiometer) incorporated into the stabilizer arms 56 of the intelligent backhoe system 22. Such a rotary position sensor may be similar, if not identical to the example rotary position sensor 85 shown in the upper right of FIG. 2, albeit integrated into the joints connecting the stabilizer arms 56 to the backhoe attachment frame 50. In this latter case, the controller architecture 74 may estimate the excavation ground height based on data from the rotary position sensor(s) indicating the rotational angle of the stabilizer arms 56 when rotated into a deployed, ground-contacting position, as taken in combination with known dimensions of the stabilizer arms 56.

The manner in which an operator interacts with the operator interface of the intelligent backhoe system 22 to control movement of the hinged backhoe assembly 46 will vary among embodiments and, perhaps, may vary based upon the particular control scheme selected by the operator for. By way of non-limiting example, an operator may control movement of the hinged backhoe assembly 46 in the following manner when a standardized control scheme is applied in which operator input commands are entered via rotational displacement of joysticks 42, 44 (FIGS. 1-3). In this example, rotation of a first joystick (e.g., the joystick 42) from a neutral or home position about a first axis (to the left or the right from the operator's perspective) causes the hoist boom 52 to swing relative to the backhoe attachment frame 50 to the operator's left or right, respectively. Rotation of the joystick 42 from the neutral position along a second axis perpendicular to the first axis (such that the top of the joystick moves closer to or further from the operator) causes the hoist boom 52 to rotate about the pivot joint 96 in an upward or downward direction, respectively. Comparatively, rotation of a second joystick (e.g., the joystick 44) from the neutral position along a first axis (to the left or the right from the operator's perspective) causes the backhoe bucket 48 to rotate about the pivot point 100 and curl inwardly or to uncurl, respectively. Finally, rotation of the joystick 44 from the neutral position along a second axis perpendicular to the first axis (such that the top of the joystick moves closer to or further from the operator) causes the dipperstick 54 to rotate about the pivot joint 98 away from or toward the hoist boom 52, respectively.

As may be appreciated from the foregoing paragraph, simultaneously controlling the various links of the hinged backhoe assembly 46 to move the backhoe bucket 48 in an intended manner, such as along a substantially linear axis, can be a challenging task under conventional control regimes. This can create difficulties for operators in attempting to control the hinged backhoe assembly 46 in a manner digging an excavation feature to a desired shape and dimensions, particularly when the tractor chassis 26 is supported by uneven or non-horizontal terrain. For these and other reasons, the opportunity for operator error in attempting to create an excavation feature (e.g., dig a trench) to a desired shape and dimensions remains undesirably elevated in conventional systems, absent the provision of the intelligent guidance functionalities described throughout this document. Consider, for example, the use case scenario illustrated in FIG. 4 in which the below-described dig depth limiting function of the intelligent backhoe system 22 is deactivated. In FIG. 4 (and in FIGS. 6-9, described below), the local ground level or height is represented by a solid line 106, while the desired floor location of an excavation feature is represented by dashed line 108. As indicated by vertical offset symbol 112, an operator has inadvertently controlled the hinged backhoe assembly 46 in a manner moving the cutting edge of the backhoe bucket 48 well-below the desired floor location of the excavation feature in this example. As a result, an operator may be required to subsequently fill in the excessive depth of the excavation feature, decreasing efficiency. Concurrently, such an operator error risks inadvertent dislodgement or breakage of pipes, conduit lines, or other such objects buried within the ground region subject to excavation. Therefore, to avoid such an undesirably situation and prevent the creation of an excavation feature having an excessive depth, the controller architecture 74 advantageously carries-out an excavation depth limiting algorithm or function in embodiments of the intelligent backhoe system 22. An example of such an excavation depth limiting function, as performed in the context of a larger intelligent boom assembly control process, will now be described in conjunction with FIG. 5.

Referring now to FIG. 5, an intelligent boom assembly control process 114 is presented in accordance with an example embodiment of the present disclosure. The intelligent boom assembly control process 114 is described below as carried-out by the controller architecture 74 of the intelligent backhoe system 22 and will thus be described as the “intelligent backhoe control process 114” hereafter. It is, however, rioted that the intelligent boom assembly control process can be performed to control or guide the movement of other types of hinged boom assemblies, regardless of the particular type of work vehicle to which the hinged boom assembly is attached and the particular excavation tool in which the boom assembly terminates. The intelligent backhoe control process 114 includes a number of process STEPS 116, 118, 120, 122, 124, 126, 128, 130, 132, 134 136 each of which is described, in turn, below. Depending upon the particular manner in which the intelligent backhoe control process 114 is implemented, each step generically illustrated in FIG. 5 may entail a single process or multiple sub-processes. Further, the steps illustrated in FIG. 5 and described below are provided by way of non-limiting example only. In alternative embodiments of the intelligent backhoe control process 114, additional process steps may be performed, certain steps may be omitted, and/or the illustrated process steps may be performed in alternative sequences.

The intelligent backhoe control process 114 commences at STEP 116 in response to the occurrence of a predetermined trigger event. In certain instances, the trigger event may be an event indicative of an operator intent to utilize the intelligent backhoe system 22 to perform an excavation operation or digging task in the immediate future, as may be indicated by interaction of the operator with the operator interface of the backhoe system 22 or by rotation of the stabilizer arms 56 into a deployed, ground-contacting position. In other instances, the controller architecture 74 may commence performance of the intelligent backhoe control process 114 in response to a different trigger event, such as in response to operator input indicating that the intelligent backhoe control process 114 is desirably performed.

After commencing the intelligent backhoe control process 114 (STEP 116), the controller architecture 74 progresses to STEP 118 of the control process 114. At STEP 118, the controller architecture 74 establishes a location and orientation of a virtual excavation floor in the 3D tool space through which the backhoe bucket 48 (or other excavation implement) moves during the ensuing excavation operation. In embodiments, the controller architecture 74 establishes the location of the virtual excavation floor based, at least in part, on an excavation depth setting and a ground height reference point. Specifically, the controller architecture 74 may determine the spatial position of a point on the virtual excavation floor by first determining the location of the ground height reference point and then moving downwardly (e.g., in a direction parallel to gravity) by the vertical distance specified by the excavation depth setting. The excavation depth setting may be entered by the operator utilizing the operator interface of the intelligent backhoe system 22 and recalled from the memory 80 when needed during STEP 118 of the intelligent backhoe control process 114. For example, the operator may interact with a GUI screen produced on the display device 40 (FIG. 2) to enter a desired dig depth as a particular number of feet or meters. In this regard, a data input arrow 138 is further shown in FIG. 5 indicating that operator settings may be considered during STEP 118 of the control process 114.

As further indicated by the data input arrow 138 in FIG. 5, the ground height reference point may be determined by recalling a default value from the memory 80 or utilizing sensor input from the additional sensors 102 when applicable. Examples of such sensors include obstacle detection systems (e.g., DME) and rotary position sensors integrated into the stabilizer arms 56, as previously described. In instances in which the excavation ground height is estimated utilizing sensor data, planform coordinates of the ground height reference point may be extrapolated, if desired, from the location at which the excavation ground height measurement is captured. For example, if utilizing stabilizer arm angular displacement to determine the excavation ground height at a location at which the stabilizer arms contact the ground, the ground height reference point may be established by extrapolating the local ground along an axis parallel to the longitudinal axis of the tractor 20 by a particular distance; e.g., by a few feet or meters. This may account for instances in which the tractor chassis 26 currently has a tilted orientation (e.g., as may be the case when the tractor 20 is located on a hill) and the ground height at the ground height reference point is vertically offset from the excavation ground height reading by a certain amount.

In still other instances, the ground height reference point may be established in another manner. For example, an intuitive approach for establishing the ground height. reference point that avoids reliance on dedicated sensors may be carried-out as follows. First, an operator is prompted (e.g., via a message or graphics generated on the display device 40) to control the hinged backhoe assembly 46 in a manner placing the backhoe bucket 48 in a ground-contacting position over or adjacent the ground region in which a trench or other excavation feature is desirably created. The operator is further prompted to provide operator input indicating when this has been done and the backhoe bucket 48 currently resides in a ground-contacting position. In response to this operator input, the controller architecture 74 then estimates the current position of the backhoe bucket 48 (and, perhaps, a lowermost surface of the backhoe bucket 48) to determine the ground height reference point. In this manner, a highly intuitive process is provided by which an operator may effectively set the backhoe bucket 48 on the ground in an excavation area, enter a desired excavation depth beneath the region below the backhoe bucket 48, and then commence the excavation operation or digging task. Additionally, in certain embodiments, an operator may also be able to specify a grade of the excavation feature floor (or otherwise rotate the virtual excavation plane about its pitch and/or roll axes) prior to conducting the excavation operation.

In addition to determining the position of the virtual excavation floor during STEP 118 of the intelligent backhoe control process 114, the controller architecture 74 further determines the orientation of the virtual excavation floor. In embodiments, the controller architecture 74 may automatically set the orientation of the virtual excavation floor relative to a frame of reference, such as the direction of gravity or the tractor chassis 26. For example, in one approach, the controller architecture 74 may orient the virtual excavation floor (e.g., a 2D plane) to extend orthogonal to the direction of gravity. In embodiments in which an operator may adjust the orientation of the virtual excavation floor, the intelligent backhoe system 22 may further enable the operator to enter a target grade or slope for the floor of an excavation feature desirably created utilizing the hinged backhoe assembly 46. The controller architecture 74 then adjusts the angular orientation of the virtual excavation floor about a roll axis, which extends parallel to the virtual excavation floor and perpendicular to a pitch axis, to correspond with the target grade entered by the operator. So too may the operator be permitted to adjust the angular orientation of the virtual excavation floor about the pitch axis in certain embodiments to provide still further flexibility in digging an excavation feature to a desired shape and geometry.

In yet other embodiments, the intelligent backhoe system 22 may enable an operator to establish other virtual boundaries, such as a virtual sidewall, of an excavation feature in addition to or in lieu of the virtual excavation floor. For example, in certain implementations, the controller architecture 74 may further determine whether an operator-commanded movement of the hinged backhoe assembly 46 will result in breach of a virtual sidewall by the backhoe bucket 48, the virtual sidewall extending from the virtual excavation floor to a ground height. When determining that an operator-commanded movement of the hinged backhoe assembly 46 will result in breach of the virtual excavation floor, the controller architecture 74 may control the EH actuation subsystem 70 to modify the operator-commanded movement in a manner preventing breach of the virtual sidewall by the backhoe bucket 48. In various implementations, the virtual sidewall or two dimensional plane may define a backface of the excavation feature desirably created utilizing the hinged backhoe assembly 46 and, specifically, the backhoe bucket 48. Further, the controller architecture 74 may command the EH actuation subsystem 70 such that a cutting edge of the backhoe bucket 48 moves along the two dimensional plane, when appropriate, to allow thorough cleaning or scraping of the excavation feature backface without breach of the backface boundary. In this manner, an operator can readily clean the backface of a trench (or other excavation feature), while lacking a direct LOS to the backface and while ensuring that the desired backface boundary of the trench will not be violated by the cutting edge of the backhoe bucket 48.

Advancing to STEP 120 of the intelligent backhoe control process 114, the controller architecture 74 next identifies a particular control mode in which the intelligent backhoe system 22 is presently operating. In certain embodiments, the intelligent backhoe system 22 may be operable in a single (standard) control mode, as previously described, in which case STEP 120 may be omitted from the control process 114. However, in other embodiments, the intelligent backhoe system 22 may be operable in multiple control or excavation tool guidance modes, which may be selectable by an operator utilizing the operator interface of the intelligent backhoe system 22. In this regard, and as touched upon previously, the intelligent backhoe system 22 may be operable in a linear control mode in which the controller architecture 74 translate operator input commands, such as rotation of either or both of the joysticks 42, 44, into linear movement of the backhoe bucket 48 along one or more axes. Such a linear control mode may be particularly beneficial when utilized in conjunction with the excavation depth limiting function, as further implemented during the course of the intelligent backhoe control process 114. Accordingly, embodiments of the intelligent backhoe system 22 may translate operator input commands into linear movement of the backhoe bucket 48 along one or both of: (i) a first axis parallel to the virtual excavation floor, and (ii) a second axis orthogonal to the virtual excavation floor. Such a linear control mode in which excavation tool movements are linearized and referenced to the virtual excavation floor may enable an operator to control motion of the excavation tool in a highly intuitive and efficient manner during an excavation operation. In other instances, the intelligent boom excavation system may be operable in such a linear control mode in which operator input commands are translated to linear movements of the excavation tool along one or more axes oriented with respect to a different frame of reference, such as the chassis of the work vehicle or with respect to the direction of gravity. Various other controls are also possible, such as a horizontal control mode executed in the cylinder (rather than tool) space.

Continuing the intelligent backhoe control process 114, the controller architecture 74 tracks the current position and motion of the backhoe bucket 48 during the control process 114 (STEP 122). As indicated by a data input arrow 140 in FIG. 5, the controller architecture 74 tracks the backhoe bucket position and motion based, at least in part, on, the tracking sensor data provided by the boom assembly tracking sensors 84 (FIG. 1), considered in conjunction with the data provided by the vehicle orientation sensors 102 indicating the current pitch and roll of the tractor chassis 26. Various different methods can be utilized to track the movement of the backhoe bucket 48 during STEP 122 (and to control movement of the backhoe bucket 48) including, for example, kinematic velocity feedforward and velocity feedback control schemes. As described above, the current angular positions of the pivot joints 96, 98, 100 may be considered by embodiments and combined with the known dimensions of the boom assembly linked to enable the controller architecture 74 to determine the present position and orientation of the backhoe bucket 48 at any given point in time. So too may linear and angular velocity estimates (if provided by the boom assembly tracking sensors 84) be utilized by the controller architecture 74 to track the position and movement of the backhoe bucket 48.

At STEP 124, the controller architecture 74 determines execution of newly-received operator input commands (or continued motion of the backhoe bucket 48 in a particular direction) will result in the breach of the virtual excavation floor (or other virtual boundary) by the backhoe bucket 48. If determining that execution of the operator input commands will not result in breach of the virtual excavation floor, the controller architecture 74 advances to STEP 128 of the intelligent backhoe control process 114. If, instead, determining that execution of the operator input commands will result in the breach of the virtual excavation floor, the controller architecture 74 progresses to STEP 126 and controls the EH actuation subsystem 70 to modify the operator-commanded movement in a manner preventing breach of the virtual excavation floor by the backhoe bucket 48. For example, the controller architecture 74 may control the EH actuation subsystem 70 to modify the operator-commanded movement such that a cutting edge of the backhoe bucket 48 moves along the virtual excavation floor in a direction indicated by the corresponding operator input command. An example of one manner in which the controller architecture 74 may control the EH actuation subsystem 70 to move a cutting of the backhoe bucket 48 along a virtual excavation floor without breach thereof is further illustrated and described below in connection with FIGS. 6-9. The controller architecture 74 then advances to STEP 128 of the intelligent backhoe control process 114.

Discussing next STEP 128, the controller architecture 74 determines whether modification of the newly-received operator input commands is appropriate to avoid the violation of other pre-established conditions, such as to avoid the exceedance of cylinder length limits. Further, in embodiments in which the intelligent backhoe system 22 desirably provides overload protection during an excavation operation, such an overload protection function may be carried-out at STEP 128 of the intelligent backhoe control process 114. To this end, during STEP 128, the controller architecture 74 may automatically (that is, without requiring operator input) control the EH actuation subsystem 70 to reduce a penetration depth in response to detection of an overload condition. For example, the controller architecture 74 may command the EH actuation subsystem 70 to move the backhoe bucket 48 is a direction away from the virtual excavation floor by a specified amount, determine if such a reduction in penetration depth has removed the overload condition, and then command further movement of the bucket 48 away from the virtual excavation floor if the overload condition has not been resolved. If the controller architecture 74 is ultimately unable to resolve the overload condition in this manner, a corresponding alert or warning may be generated by the intelligent backhoe control system 22 as, for example, a visual alert appearing on the screen of the display device 40.

In various implementations of the intelligent backhoe control process 114, an overload condition may be detected by the controller architecture 74 during STEP 128 when a load placed on the engine 32 of the tractor 20 exceeds or approaches a maximum threshold value. In other instances, the controller architecture 74 may detect the occurrence of an overload condition (and thus automatically reduce a penetration depth of the backhoe bucket 48) when an expected or anticipated velocity of the backhoe bucket. 48 exceeds the actual velocity of the backhoe bucket 48 by a predetermined margin. In still other instances, the controller architecture 74 may detect the occurrence of an overload condition when determining that the EH actuation subsystem 70 has encountered, or will soon encounter, a stall condition. In this latter instance, the controller architecture 74 may automatically control the EH actuation subsystem 70 to reduce the excavation tool penetration depth to lessen the load resisting motion of the hinged backhoe assembly 46 and thereby remove or preempt the stall condition. In certain embodiments, the controller architecture 74 may determine when such a stall condition occurs or is impending based on a hydraulic fluid pressure reading provided by one or more sensors 102 within the hydraulic flow network; e.g., if the hydraulic fluid pressure is near, equal to, or exceeds the relief pressure, the EH actuation subsystem 70 may automatically reduce the penetration depth of the excavation tool or carry-out a similar anti-stall action.

With continued reference to FIG. 5, and addressing now STEP 132 of the intelligent backhoe control process 114, the controller architecture 74 next coverts the operator input commands (whether or not modified during STEPS 126, 130) to corresponding EH valve control signals. The controller architecture 74 then transmits EH valve control signals to the appropriate valve actuators included in the EH actuation subsystem 70. The valve actuators then adjust the positions of the valve elements (e.g., spools) within the flow control valves to modify hydraulic fluid flow to the hydraulic cylinders 62, 64, 66, 68 to move the boom assembly linkage and, specifically, the backhoe bucket 48 in the desired manner. Following this, at STEP 134, the controller architecture 74 determines whether the present iteration of the intelligent backhoe control process 114 should be terminated: e.g., due completion of the current excavation task. If determining that termination of the process 114 is warranted, the controller architecture 74 advances to STEP 136 and terminates the intelligent backhoe control process 114. If, instead, determining that the intelligent backhoe control process 114 should continue, the controller architecture 74 returns to STEP 118 and the previously-described process steps repeat or loop. Thus, by repeating the above-described process steps in a relatively rapid (e.g., real-time manner), highly responsive control the hinged backhoe assembly 46 may be provided, while implementing the above-described excavation depth limiting function and/or the other intelligent control functions (e.g., overload protection and/or linear control functions) described above.

Discussing next FIGS. 6-8, there is shown an example scenario in which the controller architecture 74 commands the EH actuation subsystem 70 to move the backhoe bucket 48 along the virtual excavation floor (represented by the line 108) in a direction indicated by the operator input commands, as noted above in connection with STEP 126 of the intelligent backhoe control process 114. Specifically, in this example scenario, the controller architecture 74 controls the EH actuation subsystem 70 to coordinate the movement of the hinged backhoe assembly 46 such that a cutting edge 142 of the backhoe bucket 48 slides along the virtual excavation floor (line 108) in the direction indicated by arrow 144. To move the cutting edge 142 of the backhoe bucket 48 along the virtual excavation floor requires synchronized extension and retraction of the hydraulic cylinders 64, 66, 68, with at least the hoist cylinders 64 both extending and retracting at different phases of this motion, as indicated by arrows 146. Similarly, synchronized rotation of the hoist boom 52, the dipperstick 54, and the backhoe bucket 48 occurs about the pivot joints 96, 98, 100, as indicated by arrows 148. Stated differently, the controller architecture 74 controls the EH actuation subsystem 70 to drive the cumulative hydraulic cylinder velocity to zero in the vertical direction (in this example), while moving the cutting edge of the backhoe bucket 48 along the virtual excavation floor (line 108) in a direction corresponding to the remaining vector component of the tool movement commanded by the operator. A similar approach can be utilized to scrap the cutting edge 142 of the backhoe bucket 48 along other virtual boundaries (e.g., the above-described backface plane) of the virtual excavation feature, as desired, when prevent the bucket 48 from breaching such boundaries.

Turning lastly to FIG. 10, there is shown an isometric view of a tractor excavator 150 equipped with an intelligent backhoe system 152, as illustrated in accordance with a further example embodiment. In many respects, the intelligent backhoe system 152 is similar to the intelligent backhoe system 22 described above in connection with FIGS. 1-9 and the following description is equally applicable thereto. For example, as does the intelligent backhoe system 22, the intelligent backhoe system 152 includes a boom assembly 154 having an inner or hoist boom 156, an outer boom or dipperstick 158, and a backhoe bucket 160. The hoist boom 156 is joined to a backhoe frame 162 at a first pivot joint, the hoist boom 156 is joined to a first end of the dipperstick 158 at a second pivot joint, and a second end of the dipperstick 158 is joined to the backhoe bucket 160 at a third pivot joint. Rotation of the hoist boom 156 about the first pivot joint is controlled by extension and retraction of a hoist cylinder 164, rotation of the dipperstick 158 about the second pivot joint is controlled by extension and retraction of a dipperstick cylinder 166, and rotation or curling of the backhoe bucket 160 about the third pivot joint is controlled by extension and retraction of a bucket cylinder 168. Once again, the intelligent backhoe system 22 also includes twin stabilizer arms 170, which can be rotated between stowed (retracted) and deployed (extended) positions via extension or retraction of two stabilizer cylinders 172.

Although not shown in FIG. 10 for clarity, the intelligent backhoe system 152 likewise contains the various other components described above in connection with the backhoe system 22 including, for example, an array of boom assembly position sensors, an EH actuation subsystem, and a controller architecture. During operation of the intelligent backhoe system 152, the controller architecture tracks movement of the backhoe bucket 160 (including movement of a cutting edge 174 of the backhoe bucket 160) relative to a virtual excavation floor 176 in the mariner previously described. Here, the virtual excavation floor 176 has a planar topology and is defined by a 2D plane oriented in the 3D tool space through which the backhoe bucket 160 moves. The controller architecture further determines when an operator-commanded movement of the hinged boom assembly 154 will result in breach of the virtual excavation floor 176 by the backhoe bucket 160 based, at least in part, on the current position and motion vector of the backhoe bucket 160. When determining that an operator-commanded movement of the hinged boom assembly 154 will result in breach of the virtual excavation floor 176, the controller architecture controls the EH actuation subsystem to modify the operator-commanded movement in a manner preventing breach of the virtual excavation floor 176 by the backhoe bucket 160.

An operator may set the excavation depth represented by a double-headed arrow 178 in FIG. 10) by entering operator input into a suitable interface (e.g., a GUI field) as described above. Further, in embodiments, an operator may be able to adjust the angular position of the virtual excavation floor 176 about either or both of: (i) a roll axis 180, which extends parallel to the virtual excavation floor 176, and (ii) a pitch axis 182, which extends parallel to the virtual excavation floor 176 and perpendicular to the roll axis 180. For example, with respect to the pitch axis 182 in particular, an operator may provide input specifying a target grade or slope of the virtual excavation floor 176. The controller architecture of the intelligent backhoe system 152 then converts the target grade setting to an angular displacement of the virtual excavation floor 176 about the pitch axis 182. In this manner, an operator may set a desired grade for the trench or other excavation feature created utilizing the intelligent backhoe system 152 in an intuitive manner by entering a particular grade (e.g., plus or minus a specified number of percentage points, such as a +5% grade or a −5% grade) into the backhoe system 152 utilizing an operator interface, such as a GUI interface generated on a display screen located within the cabin of the tractor 150.

In embodiments, the controller architecture may also determine the position and orientation of one or more virtual sidewalls of the excavation feature desirably created utilizing the intelligent backhoe system 152. For example, as illustrated in FIG. 10, the controller architecture may establish the position and orientation of a backface plane 184, which extends from the virtual excavation floor 176 to the ground surface level. In certain implementations, an operator may also be able to adjust the orientation of the backface plane 184 (or other virtual sidewall) by, for example, utilizing the operator interface to rotate backface plane 184 about an axis 186, as indicated in FIG. 10 by arrows 188. Again, during operation of the intelligent backhoe system 152, the controller architecture may determine when an operator-commanded movement of the hinged boom assembly 154 will result in breach of the backface plane 184; and, when so determining, may control the EH actuation subsystem to modify the operator-commanded movement in a manner preventing breach of the backface plane 184 by the backhoe bucket 160. Specifically, the controller architecture may control the intelligent backhoe system 152 to move the cutting edge 174 of the backhoe bucket 160 along the backface plane 184 to provide a scrapping action without breach of the plane 184. In this manner, an operator is able to thoroughly clean the backface of the excavation feature created utilizing the intelligent backhoe system 152 even when lacking a direct line-of-sight to the plane 184, as shown.

Enumerated Examples of the Intelligent Boom Excavation System

The following examples of the intelligent boom excavation system are further provided and numbered for ease of reference.

1. In various embodiments, an intelligent hinged boom excavation system includes a hinged boom assembly terminating in an excavation tool, an electro-hydraulic (EH) actuation subsystem including hydraulic cylinders integrated into the hinged boom assembly, and boom assembly tracking sensors coupled to the hinged boom assembly and configured to provide tracking data indicative of excavation tool movement. A controller architecture is coupled to the EH actuation subsystem and to the boom assembly tracking sensors. The controller architecture is operable in an excavation depth limiting mode in which the controller architecture: (i) tracks a current position of the excavation tool relative to a virtual excavation floor utilizing the tracking data provided by the boom assembly tracking sensors; (ii) determines when an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor by the excavation tool based, at least in part, on the current position of the hinged boom assembly; and (iii) when determining that an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor, controls the EH actuation subsystem to modify the operator-commanded movement in a manner preventing breach of the virtual excavation floor by the excavation tool.

2. The intelligent hinged boom excavation system of example 1, wherein the controller architecture is further configured to establish a location and an orientation of the virtual excavation floor in a three dimensional (3D) tool space through which the excavation tool moves.

3. The intelligent hinged boom excavation system of example 2, wherein the controller architecture defines the virtual excavation floor as a two dimensional plane in the 3D tool space.

4. The intelligent hinged boom excavation system of example 2, wherein the controller architecture establishes the location of the virtual excavation floor based, at least in part, on an excavation depth setting and a ground height reference point.

5. The intelligent hinged boom excavation system of example 4, wherein the controller architecture establishes the ground height reference point based, at least in part, on an estimated position of the excavation tool in response to receipt of operator input indicating that the excavation tool currently resides in a ground-contacting position.

6. The intelligent hinged boom excavation system of example 4, further including a ground height sensor coupled to the controller architecture and configured to provide thereto data indicative of a ground height relative to a chassis of the work vehicle. The controller architecture establishes the ground height reference point based, at least in part, on the data provided by the ground height sensor.

7. The intelligent hinged boom excavation system of example 6, further including stabilizer arms rotatable between a stowed position and a deployed position. The ground height sensor is configured to detect an angular position of at least one of the stabilizer arms when rotated into the deployed position.

8. The intelligent hinged boom excavation system of example 2, wherein the controller architecture establishes the orientation of the virtual excavation floor based, at least in part, on operator input indicating a target grade for an excavation feature desirably created utilizing the excavation implement.

9. The intelligent hinged boom excavation system of example 1, wherein, when controlling the EH actuation subsystem to modify the operator-commanded movement in a manner preventing breach of the virtual excavation floor by the excavation tool. The controller architecture modifies the operator-commanded movement such that a cutting edge of the excavation tool moves along the virtual excavation floor in a direction indicated by an operator input command.

10. The intelligent hinged boom excavation system of example 1, wherein the controller architecture is configured to: (i) further determine whether an operator-commanded movement of the hinged boom assembly will result in breach of a virtual sidewall by the excavation tool, the virtual sidewall extending from the virtual excavation floor to a ground height; and (ii) when determining that an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor, control the EH actuation subsystem to modify the operator-commanded movement in a manner preventing breach of the virtual sidewall by the excavation tool.

11. The intelligent hinged boom excavation system of example 10, wherein the virtual sidewall includes a two dimensional plane defining a backface of an excavation feature desirably created utilizing the excavation implement.

12. The intelligent hinged boom excavation system of example 1, wherein the controller architecture is further operable in a linear control mode in which the controller architecture translates operator input commands into linear movement of the excavation tool along at least one of: (i) a first axis parallel to the virtual excavation floor; and (ii) a second axis orthogonal to the virtual excavation floor.

13. The intelligent hinged boom excavation system of example 1, wherein the controller architecture is further operable in a load limiting control mode in which the controller architecture commands the EH actuation system to reduce a penetration depth of the excavation tool in response to detection of an overload condition.

14. The intelligent hinged boom excavation system of example 13, wherein the overload condition includes a current stall or an anticipated stall of the EH actuation subsystem.

15. The intelligent hinged boom excavation system of example 1, wherein the excavation tool includes a backhoe bucket. The hinged boom assembly includes an inner boom attached to or attachable to a chassis of the work vehicle at a first pivot joint, as well as an outer boom having a first end portion joined to the inner boom at a second pivot joint and having a second end portion joined to the backhoe bucket at a third pivot joint.

Conclusion

Embodiments of a hinged boom excavation system operable in intelligent control modes, such as an intelligent backhoe system equipped with an excavation tool in the form of a backhoe bucket, have thus been provided. In various embodiments, the intelligent hinged boom excavation system is operable in an excavation depth limiting mode in which operator input commands are selectively modified or overridden to prevent breach of a virtual excavation floor (or another virtual boundary) by the excavation tool during an excavation operation. Such a virtual excavation floor may be defined as a 2D plane within a 3D tool space in embodiments, with the controller architecture determining the position of the virtual excavation floor based an excavation depth setting (a vertical spacing) between a ground level reference point and a point on the virtual excavation floor. In certain implementations, an operator may be able to adjust the orientation of the virtual excavation floor about its pitch and/or roll axes to, for example, determine the grade or slope of the excavation feature created during the excavation operation. In addition to or leu of such an excavation floor, the hinged boom excavation system may also define and prevent excavation tool breach of other virtual (e.g., planar) boundaries, such as a backface or other virtual sidewall of the excavation feature. In at least some embodiments, the controller architecture may not halt movement of the excavation tool when execution of operator input commands would result in breach of virtual excavation floor (or other virtual boundary), but rather modify the operator input commands to move the excavation tool (and, perhaps, specifically a cutting edge of the excavation tool) along the virtual excavation floor without breach thereof.

The intelligent hinged boom excavation system may also be operable in linear control modes in embodiments; and, in certain cases, the controller architecture of the excavation system may translate operator input commands (e.g., joystick displacements) to linear movement of the excavation tool along axes parallel to the virtual excavation floor and/or an axis orthogonal to the virtual excavation floor. in at least some embodiments, the intelligent hinged boom excavation system may also provide overload protection by automatically reducing a penetration depth of the excavation tool when detecting an overload condition, such as a current stall or an anticipated stall of an EH actuation subsystem. Through such intelligent control modalities, the efficiency with which operators are able to complete excavation tasks can be greatly improved, while reducing opportunities for human error and minimizing the mental workload placed on operators. Concurrently, operators are afforded greater flexibility is specifying desired dimensions and shapes of excavation features, while reliably creating the excavation features to satisfy such specifications utilizing intelligent hinged boom excavation system.

As used herein, the singular forms “a”, “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. Explicitly referenced embodiments herein were chosen and described in order to best explain the principles of the disclosure and their practical application, and to enable others of ordinary skill in the art to understand the disclosure and recognize many alternatives, modifications, and variations on the described example(s). Accordingly, various embodiments and implementations other than those explicitly described are within the scope of the following claims. 

What is claimed is:
 1. An intelligent hinged boom excavation system utilized in conjunction with a work vehicle, the intelligent hinged boom excavation system comprising: a hinged boom assembly terminating in an excavation tool; an electro-hydraulic (EH) actuation subsystem including hydraulic cylinders integrated into the hinged boom assembly; boom assembly tracking sensors coupled to the hinged boom assembly and configured to provide tracking data indicative of excavation tool movement; and a controller architecture coupled to the EH actuation subsystem and to the boom assembly tracking sensors, the controller architecture operable in an excavation depth limiting mode in which the controller architecture: tracks a current position of the excavation tool relative to a virtual excavation floor utilizing the tracking data provided by the boom assembly tracking sensors; determines when an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor by the excavation tool based, at least in part, on the current position of the hinged boom assembly; and when determining that an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor, controls the EH actuation subsystem to modify the operator-commanded movement in a manner preventing breach of the virtual excavation floor by the excavation tool.
 2. The intelligent hinged boom excavation system of claim 1, wherein the controller architecture is further configured to establish a location and an orientation of the virtual excavation floor in a three dimensional (3D) tool space through which the excavation tool moves.
 3. The intelligent hinged boom excavation system of claim 2, wherein the controller architecture defines the virtual excavation floor as a two dimensional plane in the 3D tool space.
 4. The intelligent hinged boom excavation system of claim 2, wherein the controller architecture establishes the location of the virtual excavation floor based, at least in part, on an excavation depth setting and a ground height reference point.
 5. The intelligent hinged boom excavation system of claim 4, wherein the controller architecture establishes the ground height reference point based, at least in part, on an estimated position of the excavation tool in response to receipt of operator input indicating that the excavation tool currently resides in a ground-contacting position.
 6. The intelligent hinged boom excavation system of claim 4, further comprising a ground height sensor coupled to the controller architecture and configured to provide thereto data indicative of a ground height relative to a chassis of the work vehicle; and wherein the controller architecture establishes the ground height reference point based, at least in part, on the data provided by the ground height sensor.
 7. The intelligent hinged boom excavation system of claim 6, further comprising stabilizer arms rotatable between a stowed position and a deployed position, the ground height sensor configured to detect an angular position of at least one of the stabilizer arms when rotated into the deployed position.
 8. The intelligent hinged boom excavation system of claim 2, wherein the controller architecture establishes the orientation of the virtual excavation floor based, at least in part, on operator input indicating a target grade for an excavation feature desirably created utilizing the excavation implement.
 9. The intelligent hinged boom excavation system of claim 1, wherein, when controlling the EH actuation subsystem to modify the operator-commanded movement in a manner preventing breach of the virtual excavation floor by the excavation tool, the controller architecture modifies the operator-commanded movement such that a cutting edge of the excavation tool moves along the virtual excavation floor in a direction indicated by an operator input command.
 10. The intelligent hinged boom excavation system of claim 1, wherein the controller architecture is configured to: further determine whether an operator-commanded movement of the hinged boom assembly will result in breach of a virtual sidewall by the excavation tool, the virtual sidewall extending from the virtual excavation floor to a ground height; and when determining that an operator-commanded movement of the hinged boom assembly will result in breach of the virtual excavation floor, control the EH actuation subsystem to modify the operator-commanded movement n a manner preventing breach of the virtual sidewall by the excavation tool.
 11. The intelligent hinged boom excavation system of claim 10, wherein the virtual sidewall comprises a two dimensional plane defining a backface of an excavation feature desirably created utilizing the excavation implement.
 12. The intelligent hinged boom excavation system of claim 1, wherein the controller architecture is further operable in a linear control mode in which the controller architecture translates operator input commands into linear movement of the excavation tool along at least one of: a first axis parallel to the virtual excavation floor; and a second axis orthogonal to the virtual excavation floor.
 13. The intelligent hinged boom excavation system of claim 1, wherein the controller architecture is further operable in a load limiting control mode in which the controller architecture commands the EH actuation system to reduce a penetration depth of the excavation tool in response to detection of an overload condition.
 14. The intelligent hinged boom excavation system of claim 13, wherein the overload condition comprises a current stall or an anticipated stall of the EH actuation subsystem.
 15. The intelligent hinged boom excavation system of claim 1, wherein the excavation tool comprises a backhoe bucket; and wherein the hinged boom assembly comprises: an inner boom attached to or attachable to a chassis of the work vehicle at a first pivot joint; and an outer boom having a first end portion joined to the inner boom at a second pivot joint and having a second end portion joined to the backhoe bucket at a third pivot joint.
 16. The intelligent hinged boom excavation system of claim 15, wherein boom assembly tracking sensors comprise rotary position sensors integrated into the first, second, and third pivot joints.
 17. The intelligent hinged boom excavation system of claim 1, further comprising a joystick rotatable about a first axis and coupled to the controller architecture; and wherein the controller architecture is operable in a linear control mode in which the controller architecture translates rotation of the joystick about the first axis to linear movement of the excavation implement along the virtual excavation floor.
 18. An intelligent hinged boom excavation system utilized in conjunction with a work vehicle, the intelligent hinged boom excavation system comprising: a hinged boom assembly terminating in an excavation tool; an electro-hydraulic (EH) actuation subsystem including hydraulic cylinders integrated into the hinged boom assembly; boom assembly tracking sensors coupled to the hinged boom assembly and configured to provide tracking data indicative of excavation tool movement; an operator interface configured to receive operator input commands directing movement of the hinged boom assembly; and a controller architecture coupled to the EH actuation subsystem, to the operator interface, and to the boom assembly tracking sensors, the controller architecture configured to: utilize the tracking data provided by the boom assembly tracking sensors to track a current position of the excavation tool relative to a two dimensional plane defining a boundary of an excavation feature desirably created utilizing the excavation tool; and control the EH actuation subsystem to move a cutting edge of the excavation tool along the two dimensional plane without breach thereof in response to operator input commands received via the operator interface.
 19. The intelligent hinged boom excavation system of claim 18, wherein the two dimensional plane defines a virtual excavation floor or a backface of the excavation feature.
 20. The intelligent hinged boom excavation system of claim 18, wherein the operator interface comprises a joystick rotatable about a first axis; and wherein the controller architecture is operable in a linear control mode in which the controller architecture translates rotation of the joystick about the first axis to linear movement of the excavation implement along the two dimensional plane. 